I worked as a lab assistant while an undergrad Physics major at a small college in Pennsylvania. My duties involved setting up experiments in lab rooms. Some of the experiments required electricity, which I was not that comfortable with at the time (read: terrified). A professor told me that if I learned the proper respect for electricity, all would be well. I managed to not electrocute myself over the next few years.
In the early 1990s I was accepted into the PhD program in the department of Physics at Rensselaer Polytechnic Institute. I attended on an assistantship, so I was again required to help setup labs. One class I worked in was taught by Wayne Roberge, a PhD in astrophysics from Harvard.
For one lecture session I had to setup a demonstration on electricity and magnetism that required a car battery for a power source. As I was setting up the equipment Dr. Roberge watched with concern. He looked at me and said, "You're being pretty cavalier with that battery." I asked what he meant by that. He said that the battery was dangerous, and I should be more careful with it.
"Why do you think it is dangerous?," I asked. "Well, it can produce 500 amps!," he replied. He may have been referring to the old saying "volts jolts, amps kill," an oversimplification of the fact that only small amounts of electrical current are required to stop a human heart.
At this point, I had the car battery on a table, with the terminals exposed. I grabbed the terminals, one in each hand. Dr. Roberge's eyes looked on in horror, as he thought I was about to die. Surprisingly to him, but not to me, nothing happened. I then explained to Dr. Roberge: the 12 volts of "push" supplied by a car battery is not enough to push current through dry human skin. Even if it could, the human body acts a a capacitor, which will not conduct direct current well.
Here's a guy with a PhD in Astrophysics from Harvard who didn't have a practical working knowledge of everyday electricity. Does that make him dumb, or does it make me smarter than him? No way.
The moral of the story: there are differing kinds of knowledge out there. Theoretical and practical are two kinds, but there are more. All have their place, and all have benefit. Because you think that, in theory, something is bad, doesn't necessarily mean that the reality is bad. When you look at what other people do and think, "that's dumb, I would never do that," consider that you may not have all the information that person had when that decision was made.